1. College of Earth Sciences, Jilin University, Changchun 130061, China;
2. Jilin Institute of Geological Sciences, Changchun 130012, China;
3. Qinghai Geological Survey, Xining 810000, China;
4. Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China

Petrography, geochemistry and LA-ICP-MS U-Pb dating of Beigou granites have been obtained in central Jilin of the northern margin of North China plate. LA-ICP-MS zircon U-Pb dating indicate that the granites from Beigou pluton formed during the later period of Middle Permian(~263 Ma). Beigou granites belong to calc-alkaline, metaluminous I-type granites with high K₂O content. They show strong enrichment in LREEs and LILEs (Cs,Ba,K and Sr), depletions in HREEs and HFSEs (Nb, Ta and Ti), with geochemical characteristics of adakite. The primary magma for Beigou pluton could be mainly derived from partial melting of the thickening mafic lower crust. The emplacement of Beigou pluton indicated that the initial collision in central Jilin between the north-eastern margin of the North China Plate and the Songnen terrain occurred during the later period of Middle Permian.